Tong Zhi-Bin, Gold Lyn, De Pol Anto, Vanevski Konstantina, Dorward Heidi, Sena Paola, Palumbo Carla, Bondy Carolyn A, Nelson Lawrence M
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1862, USA.
Endocrinology. 2004 Mar;145(3):1427-34. doi: 10.1210/en.2003-1160. Epub 2003 Dec 11.
We reported previously that Mater is a maternal effect gene that is required for early embryonic development beyond the two-cell stage in mice. Here we show the expressional profile of Mater and its protein during oogenesis and embryogenesis as well as its subcellular localization in oocytes. Mater mRNA was detectable earliest in oocytes of type 2 follicles, whereas MATER protein appeared earliest in oocytes of type 3a primary follicles. Both mRNA and protein accumulated during oocyte growth. In situ hybridization showed that Mater mRNA appeared progressively less abundant in oocytes beyond type 5a primary follicles. By ribonuclease protection assay, Mater mRNA was abundant in germinal vesicle oocytes, but was undetectable in all stages of preimplantation embryos. In contrast, the protein persisted throughout preimplantation development. Immunogold electron microscopic analysis revealed that MATER was located in oocyte mitochondria and nucleoli, and close to nuclear pores. Taken together, our data indicate that Mater gene transcription and protein translation are active during oogenesis, but appear inactive during early embryogenesis. Thus, Mater and its protein are expressed in a manner typical of maternal effect genes. The presence of MATER protein in mitochondria and nucleoli suggests that it may participate in both cytoplasmic and nuclear events during early development.
我们之前报道过，母源效应因子（Mater）是小鼠胚胎发育至二细胞期之后早期胚胎发育所必需的一个母源效应基因。在此，我们展示了Mater及其蛋白在卵子发生和胚胎发生过程中的表达谱，以及其在卵母细胞中的亚细胞定位。Mater mRNA最早在2型卵泡的卵母细胞中可检测到，而MATER蛋白最早出现在3a型初级卵泡的卵母细胞中。mRNA和蛋白在卵母细胞生长过程中均有积累。原位杂交显示，在5a型初级卵泡之后的卵母细胞中，Mater mRNA的丰度逐渐降低。通过核糖核酸酶保护分析，Mater mRNA在生发泡卵母细胞中丰富，但在植入前胚胎的所有阶段均未检测到。相反，该蛋白在整个植入前发育过程中持续存在。免疫金电子显微镜分析显示，MATER定位于卵母细胞的线粒体和核仁中，且靠近核孔。综上所述，我们的数据表明，Mater基因转录和蛋白翻译在卵子发生过程中活跃，但在早期胚胎发生过程中似乎不活跃。因此，Mater及其蛋白以母源效应基因的典型方式表达。MATER蛋白在线粒体和核仁中的存在表明，它可能在早期发育过程中参与细胞质和细胞核事件。
